ENCAPSULATION OF OMEGA-3 FATTY ACIDS INTO STARCH NANOPARTICLE STABILIZED PICKERING EMULSIONS

Abstract

The main purpose of the thesis is to produce starch nanoparticles to be used as an emulsion stabilizer. In the first part of the thesis, starch nanoparticles were produced via acid hydrolysis and the starch nanoparticles were characterized in terms of morphological properties and size, crystallinity and structural properties. Pickering emulsions were prepared in two different oil fractions (Φ0.6 and Φ0.8) with different oils (sunflower and corn oil). To determine the starch nanoparticle which provides the best emulsion stability, emulsions were prepared with addition of 2% (mg starch/g emulsion) starch nanoparticles. Emulsions were stored for 30 days at room conditions and phase separation was visually examined. The most stable emulsion was prepared with corn oil at Φ0.6 oil fraction when the starch nanoparticle (%2) produced with a 1:3 starch:H2SO4 ratio and 3 days hydrolysis (1:3 (3)) was used as stabilizer. In the second part of the thesis, omega-3 fatty acids were encapsulated in Pickering emulsions. Flaxseed oil was selected as the omega-3 source. The emulsions were prepared using flaxseed oil at a Φ0.2 oil fraction with the addition of 3% starch nanoparticles (1: 3 (3)). The emulsions were stored for 15 days at 25±1°C. Changes in the emulsions during storage were examined in terms of physical stability, peroxide number, pH, particle size, and zeta potential. Pickering emulsions stabilized with starch nanoparticles to encapsulate omega-3 fatty acids made flaxseed oil more resistant to primary oxidation.